Desulfurization of wide boiling range crudes



DESULFURIZATION OF WIDE BOILING RANGE CRUDES Filed May 5, 1961 July 6,1965 J. v. ELLoR ETAL 2 Sheets-Sheet 1 July 6, 1965 J, v. ELLR ETALDESULFURIZATION OF WIDE BOILING RANGE CRUDES Filed May 5, 1961 2Sheets-Sheet 2 www Nam;

mm Nm N923. IDSSQO United States Patent O 3,193,495 DESULFURIZATIGN FWIDE BGILING RANGECRUBES James V. Eller, Wilton, and George W. Gstherg,Cos

Cob, Conn., and .lohn L. Disney, Valhalla, N.Y., assignors, by mesneassignments, to Esso Standard Eastern, Inc.

Filed May 5, 1961, Ser. No. 108,167 6 Claims. (Cl. 208-211) Thisinvention relates generally to petroleum refining and more particularlyto a process for distilling whole crude petroleum and removal of sulfurIfrom a wide cut portion of the crude by a hydrodesulfurizing step, saidwide cut portion of the crude including the naphtha, kerosene and up toand through the diesel oil fractions as a single cut.

Still more particularly, this invention relates to a process of refiningwhole crude petroleum wherein the sulfur contained in the wide cutportion is removed by a catalytic hydrodesulfurizing step, which step iscarried out by utilizing hydrogen which is supplied from an outsidesource as distinguished from a process wherein hydrogen is introducedinto the system in the form of hydrogen-donor fractions or distillates.

According to a prior known process of catalytic hydrodesulfurization,the hydrogen used to carry out the sulfur removal step is manufacturedfrom the specific type of feed stock used in the distillation process;the hydrogen necessary for the sulfur removal reaction beingmanufactured from the specific type of feed stock used in thedistillation process or from recycled hydrogen-donor distillate toprovide the necessary naphthenic material to manufacture the hydrogen.That is, in that prior art process the hydrogen used in the sulfurremoval step is not produced separately and independently from anoutside source and introduced into the system in gaseous hydrogen formbut the hydrogen is introduced in the form of a hydrogen-donordistillate or fraction to provide necessary naphthenic material tomanufacture the hydrogen necessary for the sulfur removal reaction insitu in the catalytic reaction unit. In that process the hydrogen isobtained by dehydrogenation of naphthenes contained in thehydrogen-donor fractions. That type of process has been designated asautoiining In contrast, the process of this invention is one in which awide cut fraction of the crude from which the sulfur is to be removed istreated by subjecting the stream'of the Wide cut fraction in vapor,liquid or mixed phase form to the action of hydrogen in suitable form inthe presence of a catalyst in a suitable reactor vessel in which all orat least a substantial part of the hydrogen is Supplied as hydrogenindependently formed or furnished from an outside or independent source;the process of this invention being diiferent and distinct from thatprocess which has been designated as autofining. In the processaccording to this invention, the hydrogen is produced from an outsidesource; that is, it is produced independently by a hydroforming processwhich forms the hydrogen by reforming a hydrogen-containing stock bypassing the stock through a hydrogen producing reformer containing asuitable catalyst or by other known ways of producing hydrogen (H2).

Although there have been prior suggestions in the patented art ofhydrodesulfurizing processes for sulfur removal both by treatingseparate conventionally produced narrow cut fractions and also bytreating a fairly wide cut portion produced in a whole crudedistillation process, those suggested or known hydrodesulfurizationprocesses are wanting in various respects, especially where largecommercial plant operations are involved or are contemplated.

3,l3,495 Patented July 6, 1965 ice ments are admirably suited forcommercial operations and plant operation where eiciency and control ofthe characteristics of the desired end products and reduced plantinvestment and operating costs are of the utmost importance.

According to this invention a continuous process is provided ofhydrodesulfurizing a wide boiling range feed, cut from whole crudepetroleum in the distillation process and containing naphtha, keroseneand diesel oil fractions as a single portion; the process comprising thesteps of heating the crude petroleum feed; flashing the heated feed atroughly atmospheric pressure; condensing all of the resultant vapors ofthe diesel oil fraction and lighter fractions as a single portion;pumping the condensed single portion at high pressure through a preheatand furnace train, or zone, and thereby converting the single portionstream from all liquid to vapor and mixed vaporliquid state atsuper-atmospheric pressure andpassing the vaporized stream together withindependently produced gaseous hydrogen directly to a hydrodesulfurizingZone in contact with a catalyst under superatmospheric pressure, therebycausing the hydrogen to react with the surfur containing compounds ofthe vapors of the entire single portion, and thereby forming hydrogensulfide; removing the hydrogen sulfide from the stream; then reducingthe pressure to substantially atmospheric and fractionating thehydrodesulfurized product at this lowered pressure to separatedesulfurized fractions having different predetermined boiling ranges.

Although the novel features which are believed to be characteristic ofthe invention will be pointed out in the annexed claims, the inventionitself as to its objects and advantages and the manner in which it maybe carried out may be better understood by reference to the followingmore detailed description taken in connection with the Kaccompanyingdrawings forming a part hereof in which:

FIG. 1 and FIG. la when placed in juxtaposed position constitute a flowplan in diagrammatic form of a petroleum refining plant for illustratingthe process of the invention. It is to be observed that when the righthand end of FIG. 1 is joined to the left hand end of FIG. 1av thisprovides a complete ilow diagram. It will be understood that the plantis equipped with temperature and pressure indicators and pressureregulating valves and temperature regulating devices Where needed, ordesired.

Referring now to the flow diagram (FIG. l), the liquid whole crude oilenters the system through line 10 connected to a suitable source (notshown). The crude charge may be any of the typical crudesulfur-containing feeds from which it is desired to remove sulfur suchas, for example, domestic, Middle East and light South American. As aspecific example the process of the invention may be described inconnection with a whole Ararnco crude having a typical inspectionincluding sulfur content, as set forth in the following Table I.

The crude is forced by pump 11 through line 12 through heat exchanger 13(Where it is heated by an overhead stream from tower 11i, later to bedescribed) thence through line 15 through heat exchangers 15 (Where to'be described) thence through line ll through heat exchanger 19 (whereit is further heated by a liquid por- Y tion removed from fractionatortower 20, later to be described, this productbeing drawn through line55S andV pumped by pump 59 through heat exchanger @and returned to thetower through line 53a). The crude passes thence through line 2l throughheat exchanger 22. y(where it is further heated by bottoms fromfractionator tower 20), thence through line Z3 through heat exchanger Zd(where it is further heated by bottoms from splitter tower le, later tobe described) thence through line into crude preheat furnace 26. Y Y lThe crude is heated in the crude preheatrfurnace 26 to provide aconstant llash zone temperature in the splitter tower M of from about550 F. and 800 F.; and preferably a temperature at between 600 F. and650 F. but moreY desi-rably 625 F. or close thereto.Y The crude isforced through the preheat furnace at a constant pressure to maintain atower pressure in splitter. towerY la between 5 and 30 p.s.i.g. (poundsper squareeinch gaugeh'but preferably at 10 psig. or very closethereto.'l Y

The bottom stream from the splitter tower l@ passes through line 30 andis forcedV by pump '3l through line 32 through heat exchanger 24 whereit gives up heat to the crude stream llowing toward preheat furnace 26.The bottoms then pass through cooler 33, thence through drawingscomprises a reaction chamber containingcobalt molybdate as catalyst (orother knownV suitable-material many be'used as a catalyst). Suchcatalytic hydrodesulurizing reaction units are known in thev art and itis deemed unnecessary to describe this unit in further detail. And, ofcourse,'any number of units to be put into service alternately, could beprovided in particularcommercial installations.

The reactor effluent having 'been desulfurized in the catalyticdesulfurizer unit 5l is passed through line 57 and heat exchanger whereit is cooled to 400 F. and thence into iirst hash drum V at a pressureof about400 p.s.i.g.. The Voverhead vapors from flash drum e0 pass lineV34 to storage'.Y Provision can be made to pass hot Y bottoms throughline 37 toa pipe vacuum still for asphalt manufacture Vor to storage, ifdesired.

The overhead stream lcomp-rising vaporsV from-V splitter M pass throughline 40 through heat exchanger l (where its heat is given up to thecrude going to the furnace 2e) y thence through cooler Vil where theYmoving stream is cooled to'between 150 F. and 200 F. and the stream isthen passed into splitteraccumulator 42. I The appal ratus is adjustedso that the liquid in the accumulatorf comprises a wide boiling rangefraction from'the crude including naphtha, kerosene'and up to andAthrough the- VVA part ofthe condensed liquid lfrom the overhead streamfrom splitter i4 isreturned by pump i3 through line 44 to the splittertower as reilux together with reflux condensed in lineV 4S,

The streamV of wide cut fraction accumulating as liquid through lineollrthrough heat exchanger 62, thence through cooler 6? into a secondash drum o4. The stream consisting of vapors and liquid is maintained ata temperature of about 100 F. andy ata pressure of about 390 p.s.i.g. inliash drum 64.., The bottoms fromash drum ed Vare passed through line65, through heat exchanger 62 where they take up heat from'the overheadstream from flash drum 60 'and' are then combined with the bottoms fromhash drum 60 and the Vcombined bottoms are passed through lineoo througha preheat furnace 67,

l herein for convenience of description, referred to as the .second widecut fraction heater. The vapors from flash drum 54 containing H2S, lighthydrocarbons, and possibly some unreacted H2,.and otherV gases. notreadily'convdensable pass through line` 68 to an amine scrubberapparatus e9 Ywhere the' stream is scrubbed with amine solution, such asdimethynolamine or diethynolamine for removal of H231 If desired,elemental sulfur may be in accumulator 42 Vis passed through line 46'and forcedV 'Y Y by pump 47'through line 48 through asecond heatingfurnace 49 (herein referred to as the iirst'wide cut fraction preheatingfurnace); it being notedv that the stream lirst passes through a heatexchanger 50'where it takes up heat from thestream from thedesulfurization reactor Si, laterdescribed. The pump 47 provides meansto increase the pressure on the stream to any desired pressure aboveat-v mosphere and Vthe furnace 49 provides means to` heatthesulfur-containing wide cut fraction streamto any desired temperature forthe subsquent catalytic reaction and` sulfur removal step, later to bedescribed.V Uncondensed vapors and gases from accumulator 4t2pass'through line 52 to line 53 and thence to a low pressure burnerr orrecovered from the H28. The vapors from the amine scrubber e? having'theH28 Aremoved are'v compressed and recycled, as later described.

The combined bottoms 'from flash drums 60 and 64 comprises the widecut'fraction in liquidrform from the whole crude which has new ybeendesulfurized and has had removed therefrom residual uncondensed vaporsand gases including residual H2 and H28 gases. it is passed throughheater 67 and thenceinto fractionator tower 20. IThe wide cutfraction'introduced to the fractionator tower may, for convenience ofdescription, be referred to as the Vdesulfurized wide cut fraction andwill include the gas oil, kerosene, and naphtha fractions.

The Vtempera-ture maintained inthe heater 67 is such as to. provide afla-sh zone `temperature in fractionator tower 20 of between 40W F. and650 F. and preferably a temperature between 550 F. and 625 F.' and thefractions of the wide boiling range desulfurized single cut portion ofthe crude oil ar-e separated into fractions of Ycontrolled narrower`boiling range Vin the tower 20 at a Y pressure between atmosphericpressure and 100Yp.s.i.g.,

to such other use'as may be desired. Provision is made Y to pump theliquid from accumulatorAZ through lines 46a toa surge tank S4, itdesired, and thence through line 46h to pump 4?, for starting up theplant after a Shu-t;

down.

and preferably between 5 p.s.i.g. and 60 psig. The heatedstream fromifurnace V67 passes through line 70 'and the pressure on the strearnfi-sdropped so'that downstream trom vtowerr20 thev pressure is maintained atsubstantiallyY atmospheric pressure or slightly higher as mentemperaturebetween 500 F. and 800 F. and preferably to such temperature as willmaintain a temperature in the desul'furizer catalytic reactor chamber 5lat between 600 F. and 700'? F. and more desirably at about 650 7E'. Theheater 49 is referred to hereinyfor convenience ofl description, as therst wide cut fraction beaten the lpressure in the reactorl is maintainedat ,between l00 p.s.i.g. Vand 1000 p.s.i.g. and preferably between 400pretreating) Vand -a kerosene' fraction .are produced tioned Vabove. Thevarious desired fractions, such as light Yvirgin naphtha, intermediateand heavy virgin naphthas (which maybe catalytically reformed withoutrequiring as separate fractions, as'later described.

It willlbe observed from'the -ioregoingdescription that Aprior tothefinal fractionation yof the wide cut fraction to produce'the desirednarrower boiling range fractions tltlatV the sulfur-,containingY widecut fraction `Vis treated in Also the catalytic hydrodesulfurizing unitunder controlled Vconditions of high temperature and high pressurenotwithf standing thatY this apparatusand step are Ian integral part Yof Ithe whole crude refining plant and process, which operates as acontinuous process from the beginning where the feed is whole crude tothe refined separate end produc-t fractions; and the nal fractionatingsteps lare carried out at conventional atmospheric pressures or atpressures only slightly higher than atmospheric.

Referring now in more detail to the distillation and fractionation stepsfor producing the more narrow boiling .range fractions from thedesulfurized wide cut fraction, this desul-furized wide cut fraction isintroduced into fractionator tower at a pressure between atmosphericpressure and 100 p.s.i.g. and preferably between 5 psig. and 60 p.s.i.g.and `at a temperature between 400 F. and 650 F. and preferably between550 F. and 625 F. A gas oil fraction which may have a boiling range of430 F.- 630 7E., is drawn off from the tower 20, as bottoms, throughline 711 and pumped by pump 72 through heat exchanger 22 (where the hotbottoms give up heat to the countercurrent flowing whole crude passingthrough line 2l) thence through cooler 73 to storage.

A kerosene fraction, which may have a boiling range of 330 F.-430 F., isdrawn off as bottoms from stripper column 17 which is charged by a sidestream line 74 from an appropriate tray in tower 20. Stripped vaporsreturn from the stripper 17 to the tower 20 through vapor line 75.

The Vstripper bottoms product, comprising the keroseney fraction, isdrawn off through line 76 and pumped by pump 77 lthrough heat exchanger1d (where its heat is given up to the countercurrent iiow of crudethrough line 1S), thence through cooler 7 8 to storage or to a plant fortreatment with SO2 to improve its smoke point characteristics.

A heavy virgin naptha, which may have a boiling range of 300 F.-330 F.,is drawn olf as bottoms from stripper column '70 lwhich is charged by aside stre-am line Si from -an appropriate tray in fractionator tower 20.Stripped vapors return from stripper 80 through vapor line 82 to thetower. The heavy virgin naphtha is drawn off from column 80 through lineS3 and pumped by pump 84 through line S3 Iand pumped by pump S4 throughcooler 85 and thence to storage or to a plant `for use as feed stock forreforming.

An intermediate virgin naphtha, which may have a boiling range of 160F.300 F., is drawn off, as bottoms, `from stripper column S6, which ischarge-d by a side stream line 8'7 from an appropriate tray infractionator Itower Z0. Stripped vapors return from stripper S6 to thetower through vapor line 87a. The intermediate virgin naphtha is drawnoff from column 36 through line 88 land pumped by pump 89 through cooler90 to storage or to a plan-t to be used as feed stock for a reformer.

The overhead vapors from fractionator tower 20 pass through line 91through a cooler 92 and the condensed light virgin naphtha isaccumulated in fractionator accumulator 93. Uncondensed vapors and gasespass from the accumulator 93 through line 53 and thence to a lowerpressure burner or to such other use as may be desired. The lightvir-gin naphtha, which may have a boiling range of 40 F.l60 F., ispumped from the accumulator 93 by pump 94 through line 95 to astabilizer. So much of the light Virgili naphtha as may be desired forredux is returned through line 95 to the top of fractionator tower 20together with condensate from line 97 which connects line 91 wit-h line96.

The -sweet hydrocarbon vapors, residual H2 and hydrogen-containing gasesand other uncondensed gases Iare passed from the amine scrubber 69through line 100 t-o a compressor 101 where they are compressed to apressure -suflicient to be forced through line 56 together with makeuphydrogen (H2) forced through line 102 in-to line 56. Gas may be purged,as desired, from line 100 through line 103 to be used for fuel or lsuchother purpose as may be desirable.

It is signicant to note here that, although residual or unreactedhydrogen from scrubber apparatus 69 is recycled to the catalytichydrodesulfurization unit 51, the hydrogen employed in thedesulfurizin-g process is actually supplied from an outside source. Thishydrogen (H2) from an outside source may be produced in a known kind ofhydrocarbon reformer (not shown) adapted toproduce hydrogen-rich gaswhich is forced with recycled gas into the catalytic reactor S1 togetherwith the sulfur-containing wide cut fraction yfrom heater 49. The amountof hydrogen introduced into the moving stream, comprising the wide cutlfraction from which the sulfur is to be removed, should be sufiicientto bring about the necessary reaction in the hydrodesulfurization unit5l to accomplish the desired sulfur removal. Approximately 1000 s.c.f(standard cubic feet) of hydrogen per barrel of char-ge is required indesulfurizing the wide cut fraction.

The following data (set forth in Table II) will serve to illustrate theeffectiveness of the yabove described process for removal of sulfur fromthe sulfur-conta-ining wide boiling range hydrocarbons which are cutfrom the whole crude as a single fraction. inasmuch as the sulfur isremoved at this stage of the refining process, it follows that there iscorresponding sulfur decrease in the narrower boiling range productswhich are produced downstream after the stream leaves thehydrodesulfurizer unit. The sulfur removal reaction effected in thecatalytic hydrodesulfurizer unit is an integral part of the refiningprocess carried out on a continuously moving stream.

The following Table Il shows results based on a charge stock comprisingAramco crude of the kind set forth in the above Table I.

The terms and expressions which have been employed herein are used asterms of description and not of limitation, and there is no intention inthe use of such terms and expressions of excluding any equivalents ofthe features shown and described or portions thereof, but it isrecognized that various modifications are possible within the scope ofthe invention claimed.

What is claimed is:

1. A process for hydrodesulfurizing a wide boiling crude petroleum oilfeed containing naphtha, kerosene and diesel oil fractions whichcomprises the steps of heating a continuous stream of the crude oil feedto fa temperature sufficient to flash olf the diesel oil and lighterfractions stream; flashing the heated feed at a pressure betweenatmospheric and 30 p.s.i.g.; condensing all of the resulting vapors ofthe diesel oil and lighter fractions and cooling to a temperature below200 F., thereby to form a continuous wide cut liquid fraction streamcontaining the diesel oil fraction and all lighter fractions of thecrude oil; removing uncondensed gases therefrom; passing the wide cutfraction as a continuous stream through a preheat zone at a higherpressure between 100 and 1000 p.s.i.g. and heating it sufficiently tovaporize said wide cut fraction under the said higher pressure; passingsaid vaporized wide cut fraction stream together with independentlyproduced gaseous hydrogen directly as a continuous stream to ahydrodesulfurizing zone; hydrodesulfarizing the total vapors of saidcontinous wide cut fraction stream under hydrodesulfurizing condi-4tions at a temperature hetweenr600 F. and 700 Rand lat lafpressure-between 400 p.s.i;g, :and 500 p.s.i.g. and

lthereby removing `sulfur from said wide cut fraction;

thereafter fractionating the cut fraction stream at sub- Astantia-llylowerpressuretoproduce separate products of narrower boiling ranges.

2. A-process as deiinedin claim `1 in which-the widecut fraction streamafter leaving said hydrodesulfurization zone is 'cooled to below about100 F. and the pressure on said stream is reduced but maintained atabout390 p.s.i.g. and residual unreacted hydrogen then present isremoved, and the wide cut fraction -stream after removal of saidunreacted residual hydrogen is'heated to between 400 F. and 650 1F. andthen fractionated at a pressure between p.s.i.g. and-100 p.s.i.g.

3 A process as defined in'claim 2 in which the Wide cut fraction streamafter removal of unreacted residual hydrogen'is heated to between 550 Fand 625 F. and

fractionated at a pressure between 5-p.s.i.g. and 60 p.s.i.'g. "4. In alcontinuous process of rening whole crude petroleum containing unwantedsulfur wherein a wide cut fraction, including naphtha, kerosene anddiesel oil frac- Y tions, is subjected to a catalytichy-drodesulfurizat-ion and the hydrogen for said catalytic reaction isindependently and separately produced from an outside source, the stepsVwhich comprise heating 'a continuous streamV of whole crude oil feed toa temperature sufficient to ash otl the diesel oil fraction and lighterfractions lofthe Vcrude'; flashing the heated crude stream at a pressurebetween atmospheric and 30 p.s.i.g. condensing all the resulting vaporsof the adiesel oil and lighter fractions, thereby producing Va wide cutliquidrfraction containing the diesel and all lighter fractions of thecrude oi-l feed, passing the wide cut fraction as a continuous streamthrough la -iirst preheat zone at superatmospheric pres- AVsure between.100 and 1000.p.s.i.g. andheating it isui'iuncondensed `gases includingunreacted yhydrogen Vfrom the 'stream,then passing said Vwide cutfraction as a continuous stream through a second `preheat zone andheating it isufficiently to fractionate said-wide cut stream to produceseparate products of predetermined narrower boiling range.

5. In a process of refining whole crude petroleum containing unwantedsulfur wherein a wide cut fraction including naphtha, kerosene anddiesel oil fractions is subjected to Va catalytic hydrodesulfurizationand the hydrogen for said reaction is independently and separatelyproduced from an outsidesource, the steps which comprise heating acontinuous stream of whole crude oil feed to a temperature sufficientlyhigh to flash olf the fdiesel oil fraction and lighter fractions of thecrude oil feed; flashing the heated crude stream at a pressure betweenatrnospheric andV 30 p.s.,i.g. and at a temperature to `vapo'rize thecrude through the diesel oil fraction, condensing all the Yresultingvapors of the diesel oil and `lighter fractions, thereby producing awide cut liquid fraction containing the diesel and all lighter fractionsof the crude oil feed, passing the, wide cut fraction as a continuousstream through a rst preheat zone at a pressure between p.s'.i.g. and1000 p.s.i.g. and heating it to a temperature between 500 F. and 800 -Fsuiciently to vaporize said wide cut fraction Aunder thesuperatmospheric pressure, and after said stream has passed through saidfirst preheat Zone introducing'into said preheated Ystream hydrogen gaswhich has been produced from an outside source, passing said preheatedwide cut fraction t stream together with said gaseous hydrogen into acatalytic hydrodesulfurizing zone, while maintaining the pressure insaid zone between 400 p.s.i.g. and 500 p.s.i.g. and at a temperaturebetween'600" F. and 700 F., thereby removing sulfur from said wide cutfraction, then cooling said wide cut fraction stream to a temperaturebelow about 100 F. and removing residual uncondensed gases includingunrea'cted hydrogen therefrom, then passing ysaid wide cut fraction as acontinuous stream vthrough Va second preheat Zone `and Vheating ittherein to a temperature between 400 E and 600 F. and fractionating saidwide cut stream in a fractionator maintained at a pressure between 5p.s.i'.g. and 60 p.s.i.g.'toproduce from said wide cut desulfurizedfraction separate products of predeterminednarrower boiling range.

6; A process as defined in'claim 5in which the pressure on'said streamincluding the hydrogenin said hydrodesulfurizing zone is maintained atabout 440 p.s.i.g. and the temperatureat 'about 650 F. and the amount ofhydrogen introduced vinto said stream is about 1000 s.c.f. per barrelofwidecut fraction and the temperature of the stream after it leaves saidcatalytic hydrodesulfurizing Zone is reduced to belo'w 100 F. and itspressure to about 390 p.s;i.g. and the cooled wide cut fraction is thenpassed through a second Vpreheat zone where it is heated to between 550F. and 625 F. Vand in which the desulfurized wide cut fraction isfractionated'in said fractionator to produce a light virgin naphtha, anintermediate virgin naphtha, a 'heavy virgin naphtha, a kerosene and agasoil fraction.

`ReferencesCitedby the Examiner VUNITED STATES PATENTS 2,959,538 l 1l/60Weikart et al. 208-211 2,998,381 8/61 vB'uSlll'lell 208-210 ALPHONSO D.SULLIVAN, Primary Examiner.

UNITED STATES PATENT oFFIcE CERTIFICATE OF CORRECTION Patent No 3193,498 July 6, 1965 Roger Platzer et al.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 4, line 9, for "exchangers" read exchange material column 9, line7U, for "elongaed" read elongated Column l0, line 38, after "liquid"insert flow Signed and sealed this 22nd day of February 1966.

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner ofPatents

1. A PROCESS FOR HYDRODESULFURIZING A WIDE BOILING CRUDE PETROLEUM OILFEED CONTAINING NAPHTHA, KEROSENE AND DIESEL OIL FRACTIONS WHICHCOMPRISES THE STEPS OF HEATING A CONTINUOUS STREAM OF THE CRUDE OIL FEEDTO A TEMPERATURE SUFFICIENT TO FLASH OFF THE DIESEL OIL AND LIGHTERFRACTIONS STREAM; FLASHING THE HEATED FEED AT A PRESSURE BETWEENATMOSPHERIC AND 30 P.S.I.G.; CONDENSING ALL OF THE RESULTING VAPORS OFTHE DIESEL OIL AND LIGHTER FRACTIONS AND COOLING TO A TEMPERATURE BELOW200*F., THEREBY TO FORM A CONTINUOUS WIDE CUT LIQUID FRACTION STREAMCONTAINING THE DIESEL OIL FRACTION AND ALL LIGHTER FRACTIONS OF THECRUDE OIL; REMOVING UNCONDENSED GASES THEREFROM; PASSING THE WIDE CUTFRACTION AS A CONTINUOUS STREAM THROUGH A PREHEAT ZONE AT A HIGHERPRESSURE BETWEEN 100 AND 1000 P.S.I.G. AND HEATING IT SUFFICIENTLY TOVAPORIZE SAID WIDE CUT FRACTION UNDER THE SAID HIGHER PRESSURE; PASSINGSAID VAPORIZED WIDE CUT FRACTION STREAM TOGETHER WITH INDEPENDENTLYPRODUCED GASEOUS HYDROGEN DIRECTLY AS A CONTINUOUS STREAM TO AHYDRODESULFURIZING ZONE; HYDRODESULFURIZING THE TOTAL VAPORS OF SAIDCONTINOUS WIDE CUT FRACTION STREAM UNDER HYDRODESULFURIZING CONDITIONSAT A TEMPERATURE BETWEEN 600*F. AND 700*F. AND AT A PRESSURE BETWEEN 400P.S.I.G. AND 500 P.S.I.G. AND THEREBY REMOVING SULFUR FROM SAID WIDE CUTFRACTION; THEREAFTER FRACTIONATING THE CUT FRACTION STREAM ATSUBSTANTIALLY LOWER PRESSURE TO PRODUCE SEPARATE PRODUCTS OF NARROWERBOILING RANGES.